Improved mortising-machine



` UNITED STATES JOHN LEMMAN, OF

oIN'cINNA'rI, oI-IIo.Y

IMPROVED MORTISINGQMACHINE. l

Specification forming part of Letters Patent No. 35,318, dated May 20, 1862..

To @ZZ whomjt may concern:

Be it known that I, JOHN LEMMAN, of Oincinnati, Hamilton county, Ohio, have invented a new and u setul Improvement in Mortising- Machines; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the annexed drawings, making part of this specification.

This invention relates to an adjustable provision for cutting mortises otl any desired upward or downward curve or perfectly straight, or for boring onejor more round holes either in straight or curved lilies, and the invention is particularly designed for making the curved and other mortises et chair-stud".

Figure l is a perspective view of a machine embodyingI my improvement.` Fig. 2 represents a variety of mortises formed by such machine.

A is a frame.

3 is a driving-shaft, which is belted to a vibratable mandrel or shaft, (l, whose rear or fixed end journaled to the 'frame bya balljoint, D, and whose front or vibrating end carries a pod-bit, E, and is supported and guided in its desired path by means of the following arrangement:

F is a circular arc or guide-bar, of iron or steel,l terminating in journals f, coincident with thechord of said arc. The journals f are supported in heads G G which may be slid up and down and secured lat any desired height by set-screws g.

The are F may be set for an upward or a downward mortise' ot any desired camber, or for a straight mortise, by partially revolving it upon its journals, and then fixing it rigidly in position bymeans of set-screws I-I.

I is a plumber-block boxed at its upper part to afford j ournal-bearing to the forward portion of the mandrel, and terminating be low in circular socket-s i, containing sleeves J, adapted to slide upon and vibratewith the arc F.

K is a clamp supported upon a sliding rest,

L, which is vfed toward the bit by means of a lever, M. Y v

N is an adjustable stop to regulate the depth of the feed.

Then a round hole merely is desired, the only finandrel motion necessary is a simple rotary one; but for a curved. or a rectilinear slot or mortise the mandrel requires during rotation tobe slid to and fro along the arc F. This movement may be e'liected as follows:

O is a rock-arm, whose upper or free extremity connects with the block I by means ot' a pitman, P, having a ball-j oint at each end. A shaft, Q, driven by belt from the drivingshaft, carries a wrist, R, which pitmans to sleeve S, adapted to be slid up or down while the machine is in, action, by a suit of levers and rods, '.l, which maybe held to any desired point ot' adjustment by a rack, U, according l to the length of mortise desired.

V is a key for operating the arc F and the various set-screws;

Operation: For an arched mortise or row .of holes of equal camber or radius to the guidebar the lattcr is set in a vertical plane and with its apex upward or downward according to the direction desired for the curve. For any flatter curve between the above extremes the are is inclined more or less forward, while for a straight mortise or row of holes the are is fixed in a horizontal plane. The arc having been adjusted to the proper angle or inclination the heads G G are so raised or low- *ered as to bring the mandrel to a horizontal 

